21994170 has 96 divisors (see below), whose sum is σ = 59524416. Its totient is φ = 5195520.

The previous prime is 21994139. The next prime is 21994177. The reversal of 21994170 is 7149912.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21994177) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 264949 + ... + 265031.

It is an arithmetic number, because the mean of its divisors is an integer number (620046).

Almost surely, 2^21994170 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21994170, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29762208).

21994170 is an abundant number, since it is smaller than the sum of its proper divisors (37530246).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21994170 is a wasteful number, since it uses less digits than its factorization.

21994170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188 (or 177 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 21994170 is about 4689.7942385567. The cubic root of 21994170 is about 280.1791795314.

The spelling of 21994170 in words is "twenty-one million, nine hundred ninety-four thousand, one hundred seventy".